Ian

Same here, but both are in wide use so I'd count either as correct, and I'm fairly erratic in my own usage. I like Don Knuth's take (http://www-cs-faculty.stanford.edu/~knuth/email.html) (at bottom of page) on the issue (the hyphen is indicative of the newness of the concept and will fade with time), but don't have the discipline to enforce it on myself ...